1. ecstasy: E¶
Having experienced the two world wars, separations with from all thehis loved ones, agony and ecstasy, he peacefully said goodbye to this world.

While 'experience' can be a noun , 'experienced' is always a verb.

Being 'separated from', means you had no choice, being 'separated with' means you decided or took action to separate.

Last year, people were in ecstasy aboutover the stock markets.

I don't know why, this is just how you say it.

They suffered a huge loss this year.

2. radius ¶
This is the only supermarket in thea 10-mile radius.

If I know which 10 mile radius you're talking about, then you ca use "`the` 10 mile radius".

* This is the only supermarket in the 10-mile radius around my house.

3. footing ¶
When the Queen acscended to the thornrone, the UK was an empire on which the sun never sets.

This is a simple past tense sentence.
Set is irregular in that it doesn't become 'setted', it stays the same:
Set→Set

4. prophecy ¶
After the financial crisis, many economist were reflecting why there is so little prophecy about it beforehand?eling at the outcome of their ill begotten prophecy, there to which they expounded upon the strength of the economy.

A 'prophecy' is a foresight in which there is no evidence provided by its claimant.

This is a very divided country and it is hard to believe that the two parties work together in unison on this issue.

So "Unison" means something more like 'at the same time' than it does 'together'. If you mean to imply an absence of cooperation you will need to use a different word.

* The two team members worked in unison, each picking up where the other left off.

Motorists are not only those who ride a motorcycle; people driving any powered vehicle are considered to be a motorist.

Talking about banishment was once a taboo in my country.

Nothing incorrect, but you're not really applying the meaning of the word in this sentence.
* I was banished from my country, consequent to my sins.

I don't have time to read this book cover to cover but I am aware of thits more salient points in it.

I'm not sure why, but it doesn't sound natural the way it was before this correction.

The fate is fair: when heIn bestowsing you someone thing, he takes other things away from youexacts from you another.

When you use a literary sounding word like "bestows", you have follow up the rest of your sentence with language of equal caliper. This is really quite hard to do, I'm a native speaker and still I have a hard time doing it without sounding goofy.

1. ecstasy: E¶
He experienced the two world wars, and separationsed with all thehis loved ones, agony and ecstasy, h. He peacefully said goodbye to this world.

I'm not sure what you meant by this sentence, but I tried to correct it in this way. Agony and ecstacy aren't used properly here.

Last year, people were in ecstasy about the stock markets.

This sentence is grammatically correct, but if people suffered a huge loss in the stock markets, they wouldn't be happy. I suggest using another word to describe their feelings.

They suffered a huge loss this year.

2. radius ¶
This is the only supermarket in thea 10-mile radius.

3. footing ¶
When the Queen acscended to the thornrone, the UK was.K. became an empire oin which the sun never sets.

4. prophecy ¶
After the financial crisis, many economists were reflecting on why there iwas so little prophecy about it beforehand?.

"Prophecy" isn't used to describe things like financial crises. It usually describes supernatural events.

Motorists are not only those who ride a motorcycle; people driving any vehicle are considered to be a motorist.

This sentence is grammatically correct, but I want to mention that motorists are people who ride motorcycles. If you drive other vehicles, you are not considered to be a motorist.

Talking about banishment was once a taboo in my country.

The fate is fair:; when he bestows you with something, he takes other things away from you.

Last year, people were in ecstasy_____ about the stock markets.

Ecstasy means happiness. I don't see how they'd be ecstatic in this situation (?)

4. prophecy ¶
After the financial crisis, many economists were reflecting on why there is so little prophecy about it beforehand?